1. Field of the Invention
The present invention relates generally to transistors and, more particularly, to a transistor structure, such as a bipolar transistor (BT) structure or heterojunction bipolar transistor (HBT) structure, with a sidewall-defined conductive strap for an intrinsic base to extrinsic base link-up region and a method of forming the structure.
2. Description of the Related Art
As discussed in U.S. Pat. No. 6,972,443 issued on Dec. 6, 2005 to Khater, assigned to International Business Machines Corporation and incorporated herein by reference, it is desirable in bipolar transistors (BTs) and, particularly, in high performance heterojunction bipolar transistors (HBTs) to have a relatively high transit frequency fT and maximum oscillation frequency Fmax. Fmax is a function of fT and of parasitics, including parasitic capacitances and parasitic resistances. Exemplary parasitics include, but are not limited to, collector-base capacitance Ccb, base-emitter Cbe capacitance and base resistance Rb. Thus, it would be advantageous to provide transistors structure, such as a BT structure or HBT structure, with reduced collector-base capacitance Ccb and reduced base resistance Rb, as well as a method for forming such a structure.